Members of the Kingdom Fungi obtain their nutrition from organic carbon sources. The body of a fungus secretes enzymes which degrade the organic substrate on which they are growing, to yield smaller entities, which are in turn absorbed into the body of the fungus and are metabolized to provide energy to carry on its vital life processes. Molds are one manifestation of fungi which can present serious health problems to mammals because they produce dangerous mycotoxins, which are in general neurotoxins, and some of which have been found to be carcinogenic. Mycotoxins are chemical substances created by various molds generally as secondary metabolites, which are theorized to possibly play a role in either helping to prepare the substrate on which they exist for digestion, or as a defense mechanism. It has also been suggested by some that mycotoxins may be produced when the organisms are under stress, which could be related to competition/defense, or simply due to inhospitable environmental conditions. Regardless of their true biological function, the mycotoxins are a recognized health hazard.
Mycotoxins most commonly reach people from the air, via spores from an infestation of mold. Mycotoxins are also found at times in small particulates, which may comprise mold dust, which is comprised of small particles of mold that have dried. Mold spores, when inhaled, can begin to colonize in the sinuses and throughout the body, including the brain, lung, and intestinal tract, and after a period of time may lead to serious health effects.
One of the mycotoxins, aflatoxin, is produced by the fungi Aspergillus flavus and Asperfillus parasiticus. Four different aflatoxins denoted as B1, B2, G1 and G2, have been identified with B1 being the most toxic, carcinogenic and prevalent. In addition to other toxic characteristics, aflatoxin interferes with the immune system's ability to produce gamma globulin, a protein that is part of the host defense mechanism. The resulting breakdown of the immune system renders animals that have ingested such mold vulnerable to a variety of diseases.
Another very dangerous family of toxin producers is Fusarium. The toxins zearalenone, trichothecenes or moniliformin can be formed by various types of Fusarium including F. moniliforme, F. oxysporum, F. culmorum, F. avenaceum, F. equiseti, F. roseum, and F. nivale. In addition, under certain growth and environmental conditions, Stachybotrys chartarum may produce several different mycotoxins, including a very strong class known as trichothecenes. Trichothecenes are also produced by several common molds including species in the genera Acremonium (Cephalosporium), Cylindrocarpon, Dendrodochium, Myrothecium, Trichoderma, and Trichothecium. The trichothecenes are potent inhibitors of DNA, RNA, and protein synthesis, and have been well studied in animal models because of concern about their potential misuse as agents of biological warfare, due to their ability to destroy human health (mentally and physically), and never show up in an autopsy. Thus, infested homes and buildings are one of the major causes of fungal illness in industrialized nations today.
Mold requires a compatible temperature for each species. Some molds are cryophytes, which means that they favor to low temperatures for best growth, while others are thermo tolerant and adapt to a wide range of temperatures. Others still are thermopiles, and require higher temperatures for best growth. Depending on the species, these microbes can grow just about anywhere. Environmental factors (temperature, nitrogen, oxygen, etc.) provide the necessary conditions for indoor molds to thrive.
Molds need an organic source of food. It is surprising to some to see molds growing on glass, tile, stainless steel, cookware, etc.; however, such molds are in fact feeding off of some organic source deposited on these substrates (oils, films, dirt, skin cells, etc.). The fiberglass insulation that many manufacturers claim that mold does not grow on their product is a fairly true statement, however, molds nevertheless do grow on such substrates and molds disposed on such fiberglass actually thrive on organic debris that is entrapped within the interstices between the compressed fibers and on their surfaces. Mold also grows on things such as wood, fabric, leather, gypsum, fiberboard, drywall, stucco, and many insulation fibrous materials.
All molds require some form of moisture to grow; however, like temperature, the amount of moisture varies for different species. Some are xerophillic and colonize under very dry conditions, some are xerotolerant and colonize under a wide range of moisture levels, and some are hydrophilic and colonize at high moisture levels. Humidity or moisture content of the substrate can often be sufficient at levels as low as 50% relative humidity to create conditions which are problematic in many indoor environments. Thus, mold colonies can spread very easily through any HVAC system, often thriving on the surface of insulations, owing to the presence of organic matter such as sebum, dust, old spiderwebs, insect corpses, or basically any extraneous organic matter. Because of the capability of molds to thrive within heating and air conditioning ducts, or behind common drywall where moisture is present, mycotoxins may be produced within a dwelling unbeknownst to the inhabitants and distributed within the living space. When mycotoxins are produced at levels below the threshold for clinical manifestations, they may not exhibit any acute effects on the inhabitants, but rather effects over time are due to chronic persistent exposure, which may not be readily ascribed to their source. When mycotoxins are produced at or above the clinical threshold, leading to immediately recognizable adverse effects on health, it is quite common for an entire dwelling such as a home or urban building to be totally uninhabitable. In such instances, drastic measures are needed if the toxins are to be remediated. In extreme cases, demolition of the structure by razing with fire has been the means prescribed for eradicating the infestation. Owing to the magnitude of the problem of mold infestations, the efforts of several workers in the prior art have been directed at antifungal compositions and methods for their use. Typically, antimicrobials function as antifungal as well. For example, U.S. Pat. No. 4,084,747 discloses a process for the production of a composition having germicidal properties comprising contacting sodium chlorite with a substantially water soluble acid material selected from the group consisting of: organic acids and mixtures thereof with inorganic acid, wherein the contacting is carried out in aqueous media and in the presence of sufficient of the acid to lower the pH of the aqueous media to less than about 7. Further, the contacting may be carried out using ultrasonic means. This patent also provides a process for disinfecting and sterilizing which comprises contacting a germ carrier with at least a small but effective germ-killing amount of a germicidal composition obtained by reacting sodium chlorite with a substantially water soluble acid material selected from the group consisting of: organic acid and mixtures thereof with inorganic acid, the acid material comprising at least about 15% by weight of lactic acid and wherein the contacting is carried out in aqueous media and in the presence of sufficient of the acid to lower the pH of the aqueous media to less than about 7. U.S. Reissue Pat. No. 31,779 provides a germ-killing composition produced by contacting an acid material, preferably consisting of at least about 15% by weight of lactic acid, with sodium chlorite in aqueous media, the amount of acid being sufficient to lower the pH of the aqueous media to less than about 7. Methods of disinfecting and sanitizing include application of either the germ killing composition, or reactants providing in situ production thereof, to a germ carrier including substrates of various kinds as well as an enclosed air space. U.S. Pat. No. 4,880,638 teaches a biocidal composition comprising water, a source of chlorite ions, a source of chloride ions and a source of chlorate ions where the molar ratio of chlorite ions to chlorate ions is in the range from about 2:1 to about 1000:1, the mole ratio of chlorite ions to chloride ions is from about 0.1:1 to about 1000:1 and the mole ratio of chloride ions to chlorate ions is in the range from about 0.1:1 to about 1000.1; the chlorite ion source present in amounts of from about 40 grams to about 0.04 milligrams per thousand grams of water; and the composition including a pH adjusting material in an amount sufficient to adjust the pH of the mixture to above 7.0. A composition according to this invention avoids the formation of significant amounts of chlorine dioxide. U.S. Pat. No. 5,141,652 sets forth a process for reducing biological activity in a water system which process comprises: a) providing a supply of a biocidal solution, which solution comprises: (i) bromine chloride (BrCl), (ii) water, (iii) and a sufficient amount of a stabilizer consisting essentially of a halide salt or a hydrohalic acid or a mixture of halide salt and hydrohalic acid such that less than 30% of the BrCl reacts with water per year to form hypobromous acid and hydrochloric acid; and b) adding from the supply, the biocidal solution to the water system at a rate sufficient to maintain at least about 1 to 2 parts of hypobromous acid per million parts of water. U.S. Pat. No. 5,820,822 teaches compositions and methods for creating disinfecting and deodorizing chlorous acid, HClO2 and chlorous-acid derived oxychlorine species from metal chlorite salts without utilizing proton-donating acids. The chlorous acid in aqueous solutions provides its oxidative disinfecting and deodorizing action through a series of transient and stable oxychlorine degradation species. These include hypochlorous acid HOCl, dichlorine dioxide Cl2O2, and chlorine dioxide ClO2. The chlorine dioxide/chlorite complex anion Cl2O4 is also believed to provide antimicrobial and deodorizing properties. U.S. Pat. No. 6,116,254 discloses a cleaning system for a semiconductor substrate comprising: a) a cleaning tank in which a cleaning action on a semiconductor substrate is performed; b) a pure water supplying system for supplying pure water to the tank; and c) a chlorine gas supplying system for supplying a chlorine gas to the pure water existing in the tank so that the chlorine gas reacts with the pure water in the tank to generate ClOx ions, whereby the pure water containing the ClOx ions can be used as a cleaning solution for the semiconductor substrate placed in the tank. U.S. Pat. No. 6,162,371 discloses a stabilized acidic bleaching composition comprising an admixture of: a) a bleaching source of monopositive chlorine ion; b) a chlorine stabilizing agent selected from the group consisting of sulfamic acid, alkyl sulfamates, cycloalkyl sulfamates, aryl sulfamates and melamine; c) an acidic buffer present in an amount effective to provide the bleaching composition with a pH in a range of about 2 to about 6.5, wherein the acidic buffer comprises a weak acid and a salt of the weak acid; and d) water, wherein the molar ratio of chlorine stabilizing agent to the monopositive chlorine ion in the composition is greater than about 1:1. US Patent Application 2002/0072288 provides a method for antimicrobial treatment comprising applying to microbes a composition containing a diluting solvent, an antimicrobially-active solvent having a density different from the density of the diluting solvent, and an optional cosolvent, surfactant, or additional antimicrobial agent, wherein the amount of antimicrobially-active solvent or additional antimicrobial agent is sufficiently high and the amount of co-solvent or surfactant is sufficiently low so that the composition will provide greater than a 1-log order reduction in the population of spores or bacteria of Bacillus cereus within 10 seconds at 60 degrees C.
Thus, the prior art is replete with compounds and solutions of compounds useful for destroying fungi and various microbes, including the foregoing, and many other compositions and processes described in the literature. However, in cases where it is desired to eradicate a mold colony which is releasing harmful quantities of mycotoxins into an indoor environment, there exists at present no simple manner of treating such molds to their detriment without resorting to extreme techniques, especially for cases where molds are not directly accessible for physical removal. Effective methods for eradicating hidden molds include tearing into walls and dismantling ventilation systems. However, these methods are not only labor-intensive, but they also generally require the area being remediated to be evacuated during the remediation process. In addition to the loss of use of such environments being treated being inconvenient, current extreme remediation methods are expensive.
The present invention provides a method for severely inhibiting or eradicating the growth of molds from locations where molds thrive, without the need for dismantling air distribution systems or destroying the structural components of dwellings, such as walls. A method according to the invention is cost-effective and relatively non-labor intensive, as it is administered with all building systems intact. All parts and percentages stated herein are expressed on a weight basis, unless otherwise specified.